In general, a treadmill is aerobic exercise equipment capable of strengthening cardiopulmonary functions and leg muscles of a user, which is configured to allow the user to walk or run in place by rotating a running belt in an infinite orbit and to arbitrarily set an appropriate exercise condition by adjusting a rotation speed and a pitch of the running belt.
Treadmills may be broadly divided into an electric treadmill using an electric motor as a driving source, and a manual treadmill using inclination of a running belt. In the electric treadmill, a driving roller connected to the electric motor to receive driving force therefrom rotates a running belt and thus a user walks or runs at the speed of the running belt. In the manual treadmill, since two freely rotating rollers are mounted at front and rear sides and surrounded by a running belt tilted in such a manner that the front side is positioned higher than the rear side, when a user treads on the running belt, the running belt moves backward due to the weight of the user.
The treadmill has a function of adjusting a rotation speed or a pitch of a running belt to increase the effect of exercise, but does not have any particular effect other than merely running on a flat running belt.
Reflex nerves corresponding to organs of the human body are present in the soles of the feet, which are called reflex zones. About 70% of peripheral nerves are distributed in the hands and the feet. If the reflex zones are stimulated or massaged, fatigue may be relieved due to the reflex principle of peripheral nerves and the blood circulation principle.
As a conventional technology for solving disadvantages of a treadmill, Korean Utility Model Publication No. 1999-0035082 and Korean Utility Model Registration No. 0339175 disclose an acupressure running belt of a treadmill, the acupressure running belt including a plurality of acupressure projections for stimulating the soles of the feet when a user walks or runs on the running belt. In the conventional acupressure running belt, the acupressure projections integrally protrude from and rotate together with the running belt of the treadmill, which rotates using a motor and rotation shafts, and foot reflex zones are stimulated by the acupressure projections configured as convex/concave resin objects integrally provided on the surface of the running belt when a user walks or runs barefoot on the running belt of the treadmill.
However, since the conventional treadmill achieves the acupressure effect merely using the acupressure projections protruding from the surface of the running belt to a certain size, although a relatively light user does not have any problem, a relatively heavy user may feel severe pain or develop plantar fasciitis due to strong pressure of the acupressure projections on the soles of the feet.
To solve the above problem, the present applicant has proposed, in Korean Patent Registration No. 1038381, an improved “running belt acupressure apparatus of a treadmill”, in which a running belt is rotatably mounted by providing driving rollers connected to motors at two lower sides of the treadmill, a plurality of natural pebbles are located on the surface of the running belt to integrally rotate together with the running belt, stoppers are provided at two side ends of the running belt to prevent displacement of the natural pebbles, and pressure rollers having a buffer member on the surfaces thereof are mounted above and spaced apart from the driving rollers for rotating the running belt, and are connected to tension rollers and guide rollers using carrier belts mounted to carry the natural pebbles under the running belt.
In the above-described running belt acupressure apparatus of the treadmill, since the natural pebbles may form a layer, move freely, and rotate in an orbit together with the running belt, when a user treads on the natural pebbles, the pebbles naturally move due to the weight of the user. Consequently, excessive contact pressure may not be applied to the soles of the feet of the user and the user may experience the feeling of walking on a natural pebble road.
However, since the carrier belt for rotating the natural pebbles in close contact with a bottom surface of the running belt and a plurality of rollers for supporting the carrier belt are required to rotate the natural pebbles in an orbit, the running belt acupressure apparatus of the treadmill may not be easily manufactured or maintained and may not be produced at low cost due to a complex structure thereof.
To solve the above problem, the present applicant has proposed, in Korean Patent Registration No. 1194018, an “acupressure treadmill” including a body having mounted thereon a cover plate having an open treading window on a top surface thereof, front and rear rollers mounted in the body at front and rear sides, a running belt supported by the rollers to rotate in an infinite orbit, and acupressure stones rotating in an orbit together with the running belt, wherein the running belt includes a belt structure provided in a tube shape having a space filled with the acupressure stones, and including a pair of symmetrical zipper straps capable of spreading a center part of an outer surface of the belt structure to left and right sides, a zipper rail for binding separated parts of the running belt when the zipper straps are closely slid and inserted there into, and provided along the zipper straps to unbind the bound parts on the treading window, and opening guides protruding along edges of the treading window to guide the zipper straps to be separated and spaced apart from each other to expose the acupressure stones filled in the running belt.
However, the acupressure treadmill proposed by the present applicant in Korean Patent Registration No. 1194018 may not be produced or sold at low cost and may not be easily maintained or managed due to a complex structure thereof. Particularly, in all of the registered patents proposed by the present applicant, since acupressure stones such as natural pebbles are exposed all the time, the acupressure stones may be lost during exercise or foreign substances may become lodged between the acupressure stones, thereby causing consumer complaints.
To solve the above problem, the present applicant has proposed, in Korean Patent Registration No. 10-1250893, an “acupressure treadmill” including front and rear rollers mounted in a body at front and rear sides, a running belt supported by the front and rear rollers to rotate in an infinite orbit, and acupressure stones rotating in an orbit together with the running belt, wherein the running belt includes an outer sheet for forming an external surface trod on by a user, an inner sheet provided inside the outer sheet to form an internal surface, belt straps provided between and adhered to two edges of the outer and inner sheets to form a space filled with the acupressure stones between the outer and inner sheets, and a plurality of anti-sag means provided between the outer and inner sheets to suppress sagging due to the acupressure stones during orbital rotation.
However, in Korean Patent Registration No. 10-1250893 proposed by the present applicant, since the acupressure stones are located inside the external sheet, a user treads on the acupressure stones via the external sheet and thus the acupressure effect experienced by the user is greatly reduced.